A second-generation study of 427 probands with congenital heart defects and their 837 children

This study attempted to answer the question, Do mothers with congenital cardiovascular defects have more affected children than fathers with cardiac anomalies?

In the 1950s to 1960s, concern was expressed about the safety of pregnancy in women with cardiac anomalies and the possibility of inheritance.

In a prospective study over 25 years, 236 women with cardiac defects were followed through pregnancy, and their 418 offspring were examined during their 1st 3 years. A high incidence of congenital cardiac malformations was noted. Then, a retrospective study of 191 men from the same clinic group and their total family (419 children) was performed to compare the incidence of affected children between the maternal study and this subsequent paternal study.

Of 837 live children of these 427 probands, 14.1% (118) had a congenital heart defect (13.4% in the maternal study, 14.8% in the paternal study). There was no correlation with the surgical status of the proband. Concordance was somewhat greater among the children of affected mothers compared with those of affected fathers. Included in these studies were 31 high risk probands, 10 with genetic syndromes and 21 who had an affected sibling. Respectively, 53% and 41% of their children had cardiac anomalies, with a concordance > 50%; three fourths of these children had moderate to severe anomalies.

The incidence of congenital heart defects in the children was not statistically different between the maternal and paternal studies. With removal of the high risk probands from the total study group, the risk of one affected parent having a child with a cardiac anomaly was 10.7%. Of the entire 837 children, only 7.5% had moderate or severe defects.